git-crypt provides transparent encryption and decryption of files in a git repository. It allows developers to share a repository with a mix of public and private content securely. Developers without the secret key can still commit to a repository with encrypted files. The tool supports GPG and symmetric modes for encryption. It was created to protect sensitive material like SSL keys and passwords in a shared repository. git-crypt is more secure than other encryption systems, using AES-256 in CTR mode. However, it has limitations such as inability to encrypt file names or revoke access to an encrypted repository. Developers interested in encrypting entire repositories should consider using git-remote-gcrypt.
https://www.agwa.name/projects/git-crypt/